<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=, initial-scale=1.0">
    <title>Document</title>
    <style>
        .con .pink{
            background-color: pink;
        }
        .con .gold{
            background-color: gold;
        }
        /* 层级选择器 */
        div span{
            background-color: green;
        }
        span{
            color: blueviolet;
        }
    </style>
</head>
<body>
    <div class="con">
        <span>span标签-1</span>
        <a href="#" class="pink">谷歌</a>
        <a href="#" class="gold">Baidu</a>
    </div>
    <span>span标签-2</span>
</body>
</html>